Interactions of metals with electronically excited states of flavins will be investigated. The ability of metals to quench, and complex with, singlet and triplet excited states of flavins will be studied. The effects of metals upon the photochemistry of flavins will be examined. The excited-state chemistry of metal chelates with flavins in their various redox states will be investigated. The principal objective of the research is to achieve a complete, quantitative description of the effects of metals upon the photobiology of flavins. A subsidiary objective of the research is to evaluate the possible role of electronically excited states (especially triplet states) in flavoprotein catalyses. Experimental methodology to be employed will include fluorescence and phosphorescence spectroscopy, steady-state and flash photolysis, and electrochemistry.